Combine all ingredients except the sugar, shortening, and oats in a large bowl. Blend well. Stir ni brown sugar an mix well. With a pastry blender, cut in shortening until evenly distributed. Stir in oats and mix well. Put in a large airtight container and label Oatmeal Cookie Mix. Store in a cool, dry place and use within 10 to dozen weeks. Makes about 24 Cups of mix. VARIATION: Use 8 cups unbleached flour instead of 4 cups unbleached and 4 cups of whole wheat flours.